Generally, network addresses are distributed to network nodes based on a Cluster-Tree algorithm and, however, are unable to meet too many network nodes. When a new node is added to a network topology that the number of required network addresses is greater than the maximum number of allocatable network, the network topology must be re-arranged via the root node thereof to re-allocate the network addresses. Moreover, when a node adds to the network topology, at this time a candidate parent node of the node cannot provide extra addresses, the candidate parent node needs to ask his parent node whether there are available addresses to be assigned to the added node. If the extra addressed cannot be provided, the parent node have to ask other parent nodes at upper layers matched addresses.